[Detection of nordiazepam in the hair of drug addicts].

Hair samples were obtained from 36 drug addicts deceased from fatal heroin overdose. Samples were decontaminated with dichloromethane and pulverized. 50 mg of powdered hair were incubated 2 h at 40 degrees C in a phosphate buffer pH 7.6 in presence of deuterated internal standards (Nordiazepam-d5 and Oxazepam-d5) and extracted by a mixture ether/chloroform (80:20, v/v) at pH 8.4. After evaporation of the solvent, the dry extract was derivatized by silylation (BSTFA + 1% TMCS) and analyzed by gas chromatography coupled to mass spectrometry, with a detector operating in negative chemical ionization mode. 13 samples tested positive for Nordiazepam with concentrations ranging from 0.25 to 18.87 ng/mg of hair (mean: 4.16 ng/mg) and 5 positives for its metabolite, Oxazepam, with concentrations ranging from 0.11 to 0.50 ng/mg of hair (mean : 0.28 ng/mg).